It is stated that the character Fabio is Brazilian. He is not. He is a native of Tenerife, which is a city in the Canary Islands.
Although it is stated that Fabio is Brazilian, he speaks Portuguese with a thick Portugal accent.
Fabio and Matheus Silva are Portuguese from Portugal. They speak Portuguese from Portugal. Also Matheus would be Mateus in Portuguese from Portugal, because they are Portuguese from Portugal.